Drying device



March 14, 1933. J. G. OLSSON ET AL 1,901,326

DRYING DEVICE Filed.Nov. 1930 '3 Sheets-Sheet 1 frzverziars,

I Johan Ci. 0lss02zand Fans I. lifiiei z arafl March 14, 1933. J. G. OLSSON ET AL DRYING DEVICE 3 Sheets-Sheet 2 Filed Nov. 4. 1950 wN wwwm M I72 Uenions A $5012.63 QZ 98 01 and Zhzzzs ZZZ aii7f 7 March 14, 1933. J OLSSQN ET AL 1,901,326

DRYING DEVICE Filed Nov. 4, 1950 3 Sheets-Sheet 3 V Finns IE. 516222 075 Patented Mar. 14, 1933 UNITED STATES norm, swnnnlv PATENT OFFICE- .TOZEAN' G-USTAF OLSSON, or LIDINGON, AND rnANs IVAR EUGEN' srnnrons, or nnsrnni swnnnn, ASSIGNORS TO AKrInBoLAGEr SVENSKA FLAKTFABRIKEN, or srocx- DRYING nEvIcn Application filed November 4, 1930, Serial No. 193,448, and in Sweden npri1 12, 1929.

filed in Sweden,

1 '5 through the canal on wagons or the like, and

in which the drying air,'bymeans of a number of ventilators, is brought to circulate in the transversal direction of the drying device, it is of importance that the quantity of the drying air be as'large as possible because the drying when using-large quantities of air takes places more rapidly and more uniformly. Oflate endeavors have there-.

fore been made to attain larger quantities of circulation air than hitherto. This has, however, resulted in a decided increase in the power consumption.

Endeavors have been made to reduce the power consumption required for maintaining a uniform drying. A step in such a direction hasbeen taken by mounting the ventilator wheels necessary'for the'air circulation on a shaft running along the drying device. Thus, the'driving of'all the ventilators can take place from a single motor, steam-turbine or the like without losses in transmissions, belts or machinery. Though certain savings in power are gained solely through this device against older devices, the power consumption can be stillmore reduced by the present invention.

The reason for the irregular drying lies mainly in the fact that thecapacity of the drying air to take "up moistness is reduced more and more when passing through the material to be dried. If the direction ofthe air be reversed with certain equal intervals,

while the material will, at a certain point, be subjected to air having a smaller drying capacity, this is compensated for by the fact that the material in the intervalsis treated with air havingja larger drying capacity. Thus, the quantity of the circulation air may be reduced resulting in savings in power.

Attempts have hitherto been madeto solve the question of reversal of the air direction, by mounting propeller ventilators or the like on a common shaft, saidventilators supplying air in' one direction when rotating in one direction, and supplyingair in the.

opposite direction when rotating inthe other direction. 7 It is, however, known that ventilators which must supply air in opposite directions only by reversing the direction of rotation do'not operate efliciently. A far better. result is obtained if the ventilator wheels are constructed for rotation only in one direction. qAccording to tests made in a trial plant of the latter kind the savings in power amount to about 50%.

' Thereverse of the direction of circulation carried out in the present invention by simultaneous reversal of the dampers or Valves appertaining to the ventilator housings. All the dampers being compulsorily connected to each other, thereversal can take. place simultaneously by means of a I singlecontrolling means. In drying devices of they kind in question it is further of importance that. the air to be exhausted .leave the drying device saturated with moisture as fully as possible, without regard to the direction oi the air circulation within the drying device. For this purpose "the drying device is provided with a special exhaust ventilator working independently of. the circulation ventilators. special exhaust ventilator there are connected one or more suction conduits located in the vicinity of the heat batteries, prefa longitudinal section of the drying device,

Fig; 2is a horizontal sectionof the same drying device, and Fig. 3 is a cross section I To this l along-the line IIIIII of Fig. 2.;...Fig.-i

is a detail vertical sectional view on line IV-IV of Fig. 3. Fig. 5 isairagmentary horizontal sectional view: on line VV. oi

through the conduit 13 discharge into the free air. 14 are intake openings for the ventilation air. 15 are valves on the suction conduit 12. V The plant operates in theifollowing manner: When the motor 7 rotates the shaft 6, all ventilator wheels 5 rotate in their ventilator housings 4. I The air is thereby driven from the ventilator housings 4 through the vertical passages 16 to the drying canal 2. The air having passed through the material to be dried in this canal, passes and contacts with the heat batteries 3. From there the air goes further to the drying canal 1, flows through the material to be dried in this canal and returns through the to the ventilator housings 4.

drying device.

While the circulation continues in this manner, the material to be dried in the canal l is subjected to air having a larger drying capacity than the material in the canal 2.

When this has continued for a while, the dampers 89 are turned 180. The aircurrent now changes its direction throughthe Thus, the materialto be dried in thecanal 2 will be subjected to air having a larger drying capacity than the material in the canal 1. If the dampers are reversed with equal intervals, the material to be dried in the canal 1 will dry as rapidly as the material to be dried in the canal 2, and vice versa. For controlling and actuating the dampers 8 and 9, the following device shown more particularly in Fig. 5 may be used. Each damper shaft 25 is provided with a toothed segment 26 meshing :with a worm 27 and this worm is fixed on a shaft 28 extending throughout the length of thedryer. Although, only one of the dampers 8 and one of the dampers 9 are shown in Fig. 5, together with their gearing, it is to be understood that the arrangement is the same for each of the dampers required, and that any desired number of the latter may be used. The shafts 28 are connected for synchronous rotation by a chain 29 and sprockets 30, and a hand Wheel 31 having a handle 32, is provided on one of said shafts. .The quantityofair which shall be in cir- 'culation becomes about half as much as passages 17 r the same direction, paddles or the like in the ventilator wheels may be constructed more advantageously and thus the effect will be considerably improved. V

The ventilation air enters through the openings 14, and a corresponding quantity of air which is exhausted through the valves 15, passes through the conduits 12 and 11 to the exhaust ventilator 10, and is exhausted from there into the. free air through the conduit 13. I

The heat batteries 3 are mounted in a tight partition 18 which runs between the floor and the exhaust conduit. 12 along the whole drying device. Besides the passage for the air, which is formed by therbatteries, holes 19 are formed in the wall l8-adjacent the suction openings 15, and-further, an opening 1900 is formed in the samewall, near the end ofthe conduit 12 (see Fig. 1-). The object of this is. that only air which has passed the material to be dried, but not yet the heat batteries, shall be sucked into the suction conduit 12. I

in order that the airfrom the heat bat teries shall be distributed through the whole mass of the material to be dried, 'apertured walls 20 are located on each side of the row of batteries, said walls preferably having their apertures in the form of slots 21 uni formly distributed along the whole "length of the drying device.

The drying-device described above should only be considered as one embodimentof the invention. Other embodiments may be providedwithout departing from the principle oftheinvention. The-number of the canals mayffor instance, bevaried, further the drying canals and the batteries may be placed at the top, and the ventilator-,hous

spect to the canal and extending from one side of said canal to said fan housings, a second row of passages tranverse with respect to the canal and extending from the opposite side of said canal to said fan housings, and valve means for placing either row of said passages in communication with the intake sides of the fans and the other row'in communication with. the discharge sides of saidfans, allowing expeditious reversal of the fan-created airv currents without reversin the fans. i v

2. In a dr1er,'two canals for the material to "be dried,said canals having substantial- ;ly horizontal top and bottom walls, means for admitting fresh air to said canals, and

air exhausting suction conduit extending longitudinally between said canals andhaving longitudinally spaced exhaust air inlets, said suction conduit being adjacent one of said horizontal longitudinal walls, longitudinally disposed partition means between the two canals, said partition means ing from said suction conduit to the other of said horizontal walls and embodying air heating means, and means for forcing air alternately in opposite directions across said canals and through said heating means.

3. In a drier, two canals for the material to be dried, said canals having substantially horizontal top and bottom walls, means for admitting fresh air to said canals, an air exhausting suction conduit extending longitudinally between saidcanals and having longitudinally spaced exhaust air inlets, said suction conduit being adjacent one of said horizontal longitudinal walls, longitudinally disposed partition means between the two canals, said partition means extending from said suction conduit to the other of said horizontal walls and embodying air heating means, means for forcing air alternately in V oppos1te directlons across said canals and through said heating means, and vertical extendother row of air passages in communication with the discharge sides of said fans.

In witness whereof we have hereunto signed our names.

JOIIAN GUSTAF O LS SON. FRANS IVAR EUGEN STENFORS.

longitudinal apertured air distributing walls spaced outwardly from opposite sides of said suction conduit and partition means, said air distributing walls having openings adjacent said exhaust air inlets of said suction conduit".

4. In a drier, an elongated enclosure hav mg fresh air admission means, said enclosure being divided by a horizontal partition into a canal compartment and a fan housing compartment, an air exhausting suction conduit extending centrally under said horivertical longitudinal air distributing walls. I

spaced outwardly from opposite sides of said suction conduit and said vertical partition, said walls having exhaust air openingsad 'acent said exhaust air inlets of said conduit, longitudinally spaced fan housings in said fan housing compartment, fans in said houslngs respectively, a row of vertical air passages from said fan housing to the outer side of one of said canals, a second row of vertical air passages from said fan housings to the outer side of the other canal, means V for driving all of said fans in the same. CllIGCtlOIl, and means for placing either of said rows of air passages in communication with the admission sides ofsaid fans; and the 

